This section provides background information related to the present disclosure which is not necessarily prior art. This section also provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
HVAC modules can be utilized in automotive vehicles to provide conditioned air to various portions of the vehicle. For example, the HVAC module can allow for fresh air to be drawn in, or the recirculation of existing air, and can route that air across an evaporator to cool the air and/or a heater core to heat the air. The conditioned air can be routed to various locations in the passenger space of the vehicle. For example, the conditioned air can be routed to the front windshield, thereby providing a defrost function, can be routed out panel vents associated with the face area of the passenger space, or to the feet area of the passenger space and combinations thereof. Additionally, in some automotive vehicles, conditioned air may be supplied to a rear passenger space. The HVAC module may include only a single rear passageway allowing the flow of conditioned air to a single area of the rear passenger compartment or may include multiple passageways (or a partitioned passageway), allowing the conditioned air to be supplied to various locations, such as to the feet area, a body area, or a head area of the rear passenger space.
To control the various air flows through the HVAC module, mechanized doors with actuators and linkage assemblies can be utilized to control the direction of the airflow along with the partitioning of the airflow through the various passageways to provide a desired conditioned airstream to the desired areas of the passenger space. The use of mechanically actuated doors can provide positive positioning of the doors such that inadvertent or undesired airflows do not occur. However, the use of mechanically actuated doors requires a mechanism and an actuator which increases the cost of the HVAC module, along with its complexity. Thus, every use of an additional mechanically actuated door increases the cost of the HVAC module, along with its complexity. Accordingly, it would be desirable to reduce the number of mechanically actuated doors to reduce the cost and/or simplify the HVAC module.
Additionally, in some of the flow passages, air leaks can develop as a result of pressure differentials, resulting in airflow in undesired directions. The undesired airflow can take a variety of forms. For example, air from an airstream that is conditioned for the rear area may leak into the airstream conditioned for the front area due to a pressure differential and result in the air to the front area not being at the desired temperature or level of conditioning. Accordingly, it would be desirable to reduce the possibility of the various air passages cross-communicating due to pressure differentials. Furthermore, it would be advantageous if the prevention can be achieved by an economical or low cost solution.
A passive air valve for an HVAC module according to the present teachings allows air to flow through a conditioning passage in a single direction. The valve can be disposed on a downstream side of a heat exchanger that extends through at least two conditioning passages. The valve can inhibit back airflow from one of the conditioning passages to the other one of the conditioning passages. The valve does not require an actuator mechanism to economically inhibit the back airflow.
An HVAC module according to the present teachings includes a housing with an air supply passage and a blower operable to supply an air flow to the air supply passage. The housing also has an outlet passage in the housing and a conditioning passage in flow communication with the air supply passage and the outlet passage. A heat exchanger is located in the housing. There is an actively controlled door operable to selectively block flow communication between the air supply passage and the conditioning passage. There is a passive air valve allowing air to flow through the conditioning passage when originating from the air supply passage and inhibiting air from flowing through the conditioning passage when originating from the outlet passage.
An HVAC module according to the present teachings includes a housing having a main air supply passage, a first outlet passage, a first conditioning passage extending between the main air supply passage and the first outlet passage, a second outlet passage, a second conditioning passage extending between the main air supply passage and the second outlet passage, at least one first outlet communicating the first outlet passage for directing a first conditioned flow of air to a first location, and at least one second outlet communicating with the second outlet passage for directing a second conditioned flow of air to a second location different that the first location. A blower is operable to supply an air flow through the housing. A heater core is disposed in the housing and extends through both of the first and second conditioning passages. A first actively controlled door is operable to selectively block flow communication between the main air supply passage and the first conditioning passage. A second actively controlled door is operable to selectively block flow communication between the main air supply passage and the second conditioning passage. A passive air valve is disposed in the second conditioning passage on an opposite side of the heater core from the second door. The air valve allows air to flow through the heater core in the second conditioning passage when originating from the main air supply passage and inhibits air flow through the second conditioning passage when originating from the second outlet passage. The air valve thereby inhibits back airflow from the second conditioning passage to the first conditioning passage when the first and second doors block flow communication between the respective first and second conditioning passages and the main air supply passage.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.